Simulation and Experimental Design of the Locking Amplifier Based on Multisim

The output signal of the sensor in real production often submerged in complex noise, how to extract useful signal from the noise pollution of signals has become a more important research content. Lock-in amplifier can be used between noise and useful signal frequency and phase different this feature to detect a specific frequency and phase of the signal. The use of this feature of the lock-in amplifier can be very good for weak signal detection[1] and analysis. In this paper, the composition and working principle of the lock-in amplifier are studied, and the effect of the lock-in amplifier on the noise is analyzed by simulation. The results show that the locking amplifier has the function of restraining the noise, and the signal can be extracted from the bad environmental noise.